Maine’s Susan Collins on Wednesday became the first Republican senator to oppose President Donald Trump’s nominee to lead the EPA as the Senate cleared a procedural hurdle on the nomination.

The Senate voted 52-46 to end debate on the nomination of Andrew Wheeler, the acting EPA administrator, setting up his final confirmation vote for Thursday. Sens. Rick Scott, R-Fla., and Kyrsten Sinema, D-Ariz., did not vote, and Sen. Joe Manchin III, D-W.Va., an ardent supporter of the coal industry, voted against ending debate on Wheeler’s nomination.

Collins voted with the majority on the procedural motion, but she said she would vote in opposition for the final vote. Wheeler remains likely to be confirmed.

“Due to the actions Mr. Wheeler has taken during his tenure at the EPA, I will vote against his confirmation,” Collins, who likely will face a tough re-election race in 2020, said in a statement.

Collins said she believes Wheeler understands the EPA’s goals and acts ethically, unlike his predecessor, Scott Pruitt. But she added that his work to defang environmental and other climate policies is troubling.

“The policies he has supported as acting administrator are not in the best interest of our environment and public health, particularly given the threat of climate change to our nation,” Collins said. “In Maine, cars, trucks, and other vehicles produce more than 50 percent of our state’s greenhouse gas emissions. The agency’s recent efforts to halt progress in these critical areas takes us in the wrong direction.”

Senate Environment and Public Works Chairman John Barrasso, R-Wyo., said after Wednesday's vote that Wheeler is the right person to head the EPA.

“I believe he has done an outstanding job leading the EPA over the last seven months,” Barrasso said. He added , adding that he supported the agency's proposals to weaken two Obama-era policies: a rule governing federal jurisdiction over water bodies and another on emissions from the power sector.

Environmental stewardship must not be lead federally, he said. “It can’t be a top-down, Washington-knows-best approach.”

Also after the vote, Sen. Thomas R. Carper, D-Del., the ranking member on the Environment and Public Works Committee, said Wheeler had not fulfilled his promise to create a nationwide fuel economy standard.

Talks between the Trump administration, including EPA officials, and the state of California, which is pressing for higher standards than the federal government, collapsed last week after the White House broke off discussions.

At his confirmation hearing in January, Wheeler said he wanted a national plan. “Nobody wants a 50-state deal more than I do,” Wheeler told the Environment and Public Works Committee. “I haven't given up hope on that yet.”

Carper said those talks were never serious.

“These negotiations were superficial at best or duplicitous and designed to fail at worst,” Carper said on the Senate floor. The move to end talks with California shows that Wheeler can’t keep his word, Carper said.